1. Field of the Invention
Aspects of the present invention relate to a disc recording/reproducing apparatus and, more particularly to a disc cartridge loading device for receiving a disc cartridge in a disc recording/reproducing apparatus.
2. Description of the Related Art
Generally, disc recording/reproducing apparatuses that record and reproduce information using a disc-type recording medium comprising an optical disc such as a compact disc (CD) or a digital versatile disc (DVD) are widely used to record and reproduce music and images i.e., still or video images. Such disc recording/reproducing apparatuses are also widely used as a storage medium of an information processor such as a computer.
In the disc recording/reproducing apparatus, upon loading the disc-type recording medium on a tray, the tray is moved from a withdrawn position to a recording/reproducing position. Then, a turntable that constitutes a rotary driving section rises from a lower position to float up and drive the recording medium. In this state, recording or reproducing of information is performed through moving an optical pickup in a radial direction of the disc-type recording medium.
As to disc-type recording media for the disc recording/reproducing apparatus, such as the optical disc, continue to advance for high density, and a single-layer optical disc having a capacity of 25 GB has been introduced. However, as high-density disc recording/reproducing apparatuses appear, a problem of signal errors caused by foreign substances, such as dust or finger prints, is generated. To overcome such a problem, an optical disc cartridge is used.
A cartridge case has an opening which is closed by a shutter when not in use and opened by the shutter when the cartridge is mounted on the recording/reproducing position in order to perform optical recording/reproducing. Accordingly, the cartridge needs a locking device for maintaining the closed state of the shutter, and a shutter opening device for releasing the closed state of the shutter when the cartridge is mounted on the recording/reproducing position.
Japanese Patent Publication No. 2004-5880 discloses an example of the disc recording/reproducing apparatus as described above. FIG. 1 is a longitudinal section view of a disc recording/reproducing apparatus disclosed in Japanese Patent Publication No. 2004-5880, for illustrating a cartridge holder as completely inserted by a loading device. FIG. 2 illustrates the operation of a shutter opened and closed by a rack member of FIG. 1.
Referring to FIGS. 1 and 2, a cartridge holder 464 is inserted to a predetermined position from a withdrawn position by the loading device. After a disc cartridge 401 is completely inserted into the disc recording/reproducing apparatus in an arrowed direction A, a rack member 471 engaged with the cartridge holder 464 is slid in an arrowed direction B by a rack driving device. Accordingly, an inner loader 404 in the disc cartridge 401 is rotated by the rack member 471, thereby opening the shutter of the disc cartridge 401. The shutter of the disc cartridge 401 can be closed through performing the above processes in reverse order.
According to the above structure of FIGS. 1 and 2, however, since the rack member 471 is shaped similar to a stick, noise can be generated due to friction between the rack member 471 and a side of the disc cartridge 401, for example, a leading end 436bb of an unlocking arm 436a constituting a locking member 436 or a window part 435 of the disc cartridge 401. In addition, the contacting portion between the rack member 471 and the side of the disc cartridge 401 can be damaged.
In order to overcome the above and/or other problems, a cam structure has been applied in the art. A disc recording/reproducing apparatus applying the cam structure is disclosed in Japanese Patent Publication No. 2003-109282 (publication date of Apr. 11, 2003).
FIG. 3 illustrates the structure of a shutter opening and closing mechanism disclosed in the Japanese Patent Publication No. 2003-109282. Referring to FIG. 3, a shutter opening and closing mechanism 65 is provided with an opening and closing base 66 and is also provided with retainer portions 67 on both ends thereof in a lengthwise direction to receive springs 68. A rack 71 is fitted at an intermediate position of the opening and closing base 66 in the lengthwise direction thereof. The rack 71 is provided with engaging clicks 72 on both ends in the lengthwise direction thereof, respectively. These engaging clicks 72 are adapted to engage with engagement openings 73 of the opening and closing base 66. Moreover, the rack 71 is energized to protrude from the surface of the base 66 by springs 74.
Furthermore, the opening and closing base 66 is provided with a phase shift rectifying member 75 at a part on a front end side at one end of the opening and closing base 66 in the lengthwise direction thereof. The rectifying member 75 is provided with a pair of engaging clicks 76. These engaging clicks 76 are engaged with engagement openings 77, and are biased by a spring 78 in a direction in which the engaging clicks 76 project. Moreover, another phase shift rectifying member 79 is fitted on a rear end side of the base 66. Engaging clicks 80 on both ends of the phase shift rectifying member 79 engage with engagement openings 81 of the base 66. Moreover, the phase shift rectifying member 79 is biased by a spring 82 in a direction in which the phase shift rectifying member 79 springs out.
However, the above structure as disclosed in Japanese Patent Publication No. 2003-109282 is very complicated and requires many parts, thereby promoting an increased cost and size of the apparatus.